[Milsurplus] FW: SCR-73 mention in Radio Boys books

[Hubert Miller]

Forwarded from Northwest Vintage Radio Society  ( NWVRS, Portland OR ) for possible interest: 
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The references in the Radio Boys books are mostly in Trailing a Voice,  and The Radio Boys With the Forest Rangers.  While there is technical info dotted throughout the books, most of the detailed discussion is in one or two specific sections of each. The discussion in the Forest Rangers covers mainly the importance of airborne radio and how it is deployed, but the technical aspects are given in Trailing a Voice which also goes into how radio is used in fire-fighting.  Following out of a discussion of QRM the Ranger they are speaking with moves on to some technical details of the sets they use:
 
            "You see," he explained, we use a special type of transmitting outfit aboard our fire-detection craft. It's called the SCR-Seventy-three.  The equipment obtains its power from a self-excited inductor type alternator  This is propelled by a fixed wooden-blade air fan.  In the streamline casing of the alternator the rotary spark gap, alternator, potential transformer, condenser and oscillation transformer are self-contained.  Usually the alternator is mounted on the underside of the fuselage where the propellor spends its in the form of an air stream.  The telegraph sending keys, field and battery switch, dry battery, variometer and antenna reel are the only units included inside the fuselage.
"           The type of transmitter is a simple rotary gap, indirectly excited spark and provided with nine taps on the inductance coil of the closed oscillating circuit.  Five varying tooth discs for the rotary spark gap yield five different signal tones and nine different wave lengths are possible."
 
Which is pretty heady stuff for a book intended for boys in their early teens.
 
Actually, going through the books isn't tedious at all. They make quite entertaining reading in their own right, and since they were written throughout the 1920s, the technical descriptions give a sort of popular history of radio development during that important decade.  Several are available at the Gutenberg Project website.
-oz  
Larry Osborne Ph.D. (Ret.)
No longer an authority on anything
KI7UFC


>On Sun, Aug 25, 2019 at 11:56 PM Hubert Miller 
Larry, do you recall which specific books in the series touch on Forest Service  radios ? 
I suspect it would be tedious to wade through a bunch of these.
thanks-
Hue